Explainer · Plain-language
What is open access?
Open access (OA) means free online availability of peer-reviewed research literature, with permission for reuse. Most commonly under a CC BY licence. Defined in the 2002 Budapest Open Access Initiative; mandated by virtually every major funder in 2026.
The step most authors miss
Doing CRediT right? Don’t stop at the statement.
A CRediT statement credits you inside one paper. The recognition CRediT was built for happens when those roles are tied to you, persistently. Sign in with your ORCID — free — and claim your CRediT contributions on casrai.org, the home of the standard. They become a verified, portable part of your identity, not a line that disappears into one PDF.
Free: claim your contributions, then export a journal-ready CRediT statement, schema.org structured data, JATS XML, CSV or BibTeX — and preview your public profile. A membership publishes that profile publicly and verifies the journals you serve.
Routes to OA
Gold OA — publication in a fully open-access journal; APC paid by author/institution/funder. Diamond OA — publication in a fully OA journal at no cost to author (funded by consortium/community). Green OA — publication in any journal with parallel deposit of the accepted manuscript in an open repository. Hybrid OA — subscription journal with per-article OA option (controversial).
The Berlin / Budapest definitions
Open access was formalised in the Budapest Open Access Initiative (2002), Bethesda Statement (2003), and Berlin Declaration (2003). All three require both free access AND reuse rights — typically a CC BY licence.
Funder mandates
Plan S (Sep 2018), UKRI OA Policy (Apr 2022), NIH 2024 Public Access Policy, NSF (effective 2026), Wellcome OA (2021), Horizon Europe (2021), Australian ARC + NHMRC, Tri-Agency Canada — virtually every major funder now mandates OA.
OA vs preprints
Preprints are pre-peer-review manuscripts deposited on a preprint server (arXiv, bioRxiv, medRxiv, ChemRxiv, SSRN). They're free to read but not yet peer-reviewed. Most major funders count preprint deposit as one valid pathway to compliance.
Key facts
At a glance
- Defined: Budapest OAI (2002), Berlin Declaration (2003)
- Routes: Gold, Diamond, Green, Hybrid
- Licence: Typically CC BY (Plan S mandate)
- Adoption: ~50% of newly-published research in 2026
- Mandated: UKRI, Plan S, NIH, NSF, ERC, Wellcome, Horizon Europe, Tri-Agency, ARC, NHMRC
Common misconceptions
What people often get wrong
Often heard: "Free to read" = open access.
Actually: Not quite — OA requires reuse rights too. A paper readable on a publisher's site but not redistributable is not strictly OA.
Often heard: OA means the author pays an APC.
Actually: Diamond OA and Green OA involve no APC. Plan S explicitly prohibits authors from being charged personally.
Going deeper
